Android example source code file (ListOfItemsTallerThanScreenTest.java)

This example Android source code file (ListOfItemsTallerThanScreenTest.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

activityinstrumentationtestcase, android, exception, largetest, listofitemstallerthanscreentest, listview, mediumtest, test, ui, view, widget

The ListOfItemsTallerThanScreenTest.java Android example source code

/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.widget.listview.arrowscroll;

import android.test.ActivityInstrumentationTestCase;
import android.test.suitebuilder.annotation.LargeTest;
import android.test.suitebuilder.annotation.MediumTest;
import android.widget.ListView;
import android.view.View;
import android.view.KeyEvent;
import android.widget.listview.ListOfItemsTallerThanScreen;

public class ListOfItemsTallerThanScreenTest
        extends ActivityInstrumentationTestCase<ListOfItemsTallerThanScreen> {

    private ListView mListView;
    private ListOfItemsTallerThanScreen mActivity;


    protected void setUp() throws Exception {
        super.setUp();
        mActivity = getActivity();
        mListView = getActivity().getListView();
    }

    public ListOfItemsTallerThanScreenTest() {
        super("com.android.frameworks.coretests", ListOfItemsTallerThanScreen.class);
    }

    @MediumTest
    public void testPreconditions() {
        assertNotNull(mListView);
        assertEquals("should only be one visible child", 1, mListView.getChildCount());
        final int amountOffScreen = mListView.getChildAt(0).getBottom() - (mListView.getBottom() - mListView.getListPaddingBottom());
        assertTrue("must be more than max scroll off screen for this test to work",
                amountOffScreen > mListView.getMaxScrollAmount());
    }

    @MediumTest
    public void testScrollDownAcrossItem() {
        final View view = mListView.getSelectedView();
        assertTrue(view.isSelected());

        assertEquals(mListView.getListPaddingTop(),
                view.getTop());

        assertTrue("view must be taller than screen for this test to be worth anything",
                view.getBottom() > mListView.getBottom());

        // scroll down until next view is peeking ahead
        int numScrollsUntilNextViewVisible = getNumDownPressesToScrollDownAcrossSelected();

        for (int i = 0; i < numScrollsUntilNextViewVisible; i++) {
            assertEquals("after " + i + " down scrolls across tall item",
                    mListView.getListPaddingTop() - mListView.getMaxScrollAmount() * i,
                    view.getTop());
            sendKeys(KeyEvent.KEYCODE_DPAD_DOWN);
        }

        // at this point, next view should be on screen peeking ahead, but we haven't given
        // it selection yet
        assertEquals("child count", 2, mListView.getChildCount());
        assertEquals("selected position", 0, mListView.getSelectedItemPosition());
        assertTrue("same view should be selected", view.isSelected());
        final View peekingView = mListView.getChildAt(1);
        assertEquals(view.getBottom(), peekingView.getTop());
    }

    @MediumTest
    public void testScrollDownToNextItem() {
        final int numPresses = getNumDownPressesToScrollDownAcrossSelected();
        assertEquals(1, mListView.getChildCount());

        for (int i = 0; i < numPresses; i++) {
            sendKeys(KeyEvent.KEYCODE_DPAD_DOWN);
        }
        // remember top of peeking child
        final int topOfPeekingNext = mListView.getChildAt(1).getTop();

        // next view is peeking, now press one more time
        sendKeys(KeyEvent.KEYCODE_DPAD_DOWN);

        // old view should not have selection
        assertFalse(mListView.getChildAt(0).isSelected());

        // next view should now have selection, and be scrolled another a third of the list
        // height
        assertEquals(2, mListView.getChildCount());
        final View next = mListView.getChildAt(1);
        assertTrue("has selection", next.isSelected());
        assertEquals(topOfPeekingNext - (mListView.getMaxScrollAmount()), next.getTop());
    }

    @MediumTest
    public void testScrollFirstItemOffScreen() {
        int numDownsToGetFirstItemOffScreen =
                (mListView.getSelectedView().getHeight() / mListView.getMaxScrollAmount()) + 1;

        for (int i = 0; i < numDownsToGetFirstItemOffScreen; i++) {
            sendKeys(KeyEvent.KEYCODE_DPAD_DOWN);
        }
        getInstrumentation().waitForIdleSync();

        assertEquals("should be at next item",
                1, mListView.getSelectedItemPosition());

        final int listTop = mListView.getTop() + mListView.getListPaddingTop();
        assertTrue("top of selected view should be above top of list",
                mListView.getSelectedView().getTop() < listTop);

        assertEquals("off screen item shouldn't be a child of list view",
                1, mListView.getChildCount());
    }

    @LargeTest
    public void testScrollDownToLastItem() {
        final int numItems = mListView.getAdapter().getCount();

        int maxDowns = 20;
        while (mListView.getSelectedItemPosition() < (numItems - 1)) {
            sendKeys(KeyEvent.KEYCODE_DPAD_DOWN);
            if (--maxDowns <= 0) {
                fail("couldn't get to last item within 20 down arrows");
            }
        }
        getInstrumentation().waitForIdleSync();

        // press down enough times to get to bottom of last item
        final int numDownsLeft = getNumDownPressesToScrollDownAcrossSelected();
        assertTrue(numDownsLeft > 0);
        for (int i = 0; i < numDownsLeft; i++) {
            sendKeys(KeyEvent.KEYCODE_DPAD_DOWN);
        }
        // one more time to get across last item
        sendKeys(KeyEvent.KEYCODE_DPAD_DOWN);
        getInstrumentation().waitForIdleSync();

        assertEquals(numItems - 1, mListView.getSelectedItemPosition());
        final int realBottom = mListView.getHeight() - mListView.getListPaddingBottom();
        assertEquals(realBottom, mListView.getSelectedView().getBottom());

        assertEquals("views scrolled off screen should be removed from view group",
                1, mListView.getChildCount());
    }

    @MediumTest
    public void testScrollUpAcrossFirstItem() {
        final int listTop = mListView.getListPaddingTop();
        assertEquals(listTop, mListView.getSelectedView().getTop());
        final int numPresses = getNumDownPressesToScrollDownAcrossSelected();
        for (int i = 0; i < numPresses; i++) {
            sendKeys(KeyEvent.KEYCODE_DPAD_DOWN);
        }
        assertEquals(2, mListView.getChildCount());
        for (int i = 0; i < numPresses; i++) {
            sendKeys(KeyEvent.KEYCODE_DPAD_UP);
            assertEquals(1, mListView.getChildCount());
        }
        assertEquals(listTop, mListView.getSelectedView().getTop());
    }

    /**
     * Assuming the selected view is overlapping the bottom edge, how many times
     * do I have to press down to get beyond it so that either:
     * a) the next view is peeking in
     * b) the selected view is the last item in the list, and we are scrolled to the bottom
     * @return
     */
    private int getNumDownPressesToScrollDownAcrossSelected() {
        View selected = mListView.getSelectedView();
        int realBottom = mListView.getBottom() - mListView.getListPaddingBottom();
        assertTrue("view should be overlapping bottom",
                selected.getBottom() > realBottom);
        assertTrue("view should be overlapping bottom",
                selected.getTop() < realBottom);

        int pixelsOffScreen = selected.getBottom() - realBottom;
        return (pixelsOffScreen / mListView.getMaxScrollAmount()) + 1;
    }

}